US20030045183A1 - Water jet propulsion apparatus - Google Patents
Water jet propulsion apparatus Download PDFInfo
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- US20030045183A1 US20030045183A1 US10/231,315 US23131502A US2003045183A1 US 20030045183 A1 US20030045183 A1 US 20030045183A1 US 23131502 A US23131502 A US 23131502A US 2003045183 A1 US2003045183 A1 US 2003045183A1
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- cap
- water jet
- jet propulsion
- propulsion apparatus
- bearing
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 238000003780 insertion Methods 0.000 claims description 12
- 230000037431 insertion Effects 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H11/00—Marine propulsion by water jets
- B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
- B63H11/10—Marine propulsion by water jets the propulsive medium being ambient water having means for deflecting jet or influencing cross-section thereof
- B63H11/103—Marine propulsion by water jets the propulsive medium being ambient water having means for deflecting jet or influencing cross-section thereof having means to increase efficiency of propulsive fluid, e.g. discharge pipe provided with means to improve the fluid flow
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H11/00—Marine propulsion by water jets
- B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
- B63H11/04—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps
- B63H11/08—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps of rotary type
Definitions
- the present invention relates to a water jet propulsion apparatus, and more particularly to a water jet propulsion apparatus for use in a watercraft.
- FIG. 6 A water jet propulsion apparatus of the background art, e.g., corresponding to Japanese Patent Laid-open No. Hei-5-105189, the entirety of which is hereby incorporated by reference, is shown in FIG. 6.
- the water jet propulsion apparatus has a duct 2 forming a channel in communication with an intake 1 a provided on the bottom of a hull 1 , an impeller 3 disposed in the duct 2 , a bearing 4 of the impeller provided in the duct 2 , and a cap 5 closing the rear end of the bearing 4 .
- the duct 2 includes an impeller duct 2 a, a stationary vane duct 2 b, and a nozzle 2 c.
- the bearing 4 is formed integrally with the stationary vane duct 2 b via a stationary vane 2 b 1 .
- the impeller 3 is fixed to a drive shaft 6 .
- the front end of the drive shaft 6 is coupled to the output shaft of an engine (not-shown) mounted on the hull 1 , and the rear end 6 a is rotatably supported by the bearing 4 .
- a stationary vane 5 a is formed on the external face of the cap 5 , and a stationary vane 2 c 1 is integrally formed on the internal face of the nozzle 2 c.
- a deflector 7 is rotatably attached to the rear part of the nozzle 2 c.
- the present inventors have determined that the rotational component of a water stream very close to the external face of the cap 5 cannot be sufficiently reduced with the systems of the background art. Since the stationary vane 5 a is formed on the external face of the cap 5 , the cap 5 , including the stationary vane 5 a, is relatively large. In addition, the stationary vane 5 a formed on the external face of the cap 5 and the stationary vane 2 c 1 formed on the internal face of the nozzle 2 c have to be repositioned.
- the present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art.
- An object of the invention is to provide a water jet propulsion apparatus that can solve the above identified problems and/or sufficiently reduce the rotational component of the water stream close to the external face of the cap.
- An additional object of the present invention is to reduce the size of the cap while achieving the aforementioned objects.
- An additional object of the present invention is to provide a cap that does not require positioning between the cap and other stationary vanes.
- a water jet propulsion apparatus comprising a duct forming a channel; an impeller being disposed within the duct; a bearing of the impeller provided in the duct, the bearing having a rear end and a front end; a cap closing the rear end of the bearing, the cap having an external face and a front portion; and at least one stream straightening groove being formed in the external face of the cap.
- a method of reducing a rotational component of a flow stream exiting a water jet propulsion apparatus for a watercraft comprising installing a cap closing a rear end of a bearing for an impeller within a duct, the cap having an external face and a front portion; and forming at least one flow stream straightening groove within the external face of the cap for reducing the rotational component of the flow stream.
- the water jet propulsion apparatus including a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, a cap closing the rear end of the bearing, and stream straightening grooves formed in the external face of the cap provides a rotational component of a water stream close to the external face of the cap that is significantly reduced by the stream straightening grooves.
- the stream straightening grooves since it is sufficient to form the stream straightening grooves, e.g., not a stream straightening plate (stationary vane) in the external face of the cap, a number of stream straightening grooves can be formed in the limited outer circumference length of the cap whose diameter is typically relatively small. Accordingly, the rotational component of the water stream close to the external face of the cap can be sufficiently reduced with the present invention. In addition, the size of the cap can be reduced. Since stream straightening grooves are formed in the external face of the cap it becomes unnecessary to position the cap with the other stationary vanes. Therefore, formation of the stream straightening grooves in the external face of the cap is particularly effective in the case where a stationary vane is formed facing toward the portion facing the cap, e.g., in the internal face of the duct.
- a stationary vane is formed facing toward the portion facing the cap, e.g., in the internal face of the duct.
- FIG. 1 is a partial, side view of a small, planing watercraft having a water jet propulsion apparatus according to an embodiment of the present invention
- FIG. 2 is a plan view of the watercraft shown in FIG. 1;
- FIG. 3 is a sectional view showing a water jet propulsion apparatus according to the present invention.
- FIG. 4 is a rear view of the water jet propulsion apparatus according to the present invention.
- FIG. 5 a is a side view of a cap according to the present invention.
- FIG. 5 b is a right side view, when viewed from the rear of the watercraft body, of a cap according to the present invention.
- FIG. 5 c a sectional view of a cap taken along line c-c of FIG. 5 b,
- FIG. 5 d is a cross section of a cap taken along line d-d of FIG. 5 b;
- FIG. 6 is a sectional view of a propulsion apparatus of the background art.
- FIG. 1 is a partial, side view of a small, planing watercraft having a water jet propulsion apparatus according to an embodiment of the present invention.
- FIG. 2 is a plan view of the watercraft shown in FIG. 1.
- FIG. 3 is a sectional view showing a water jet propulsion apparatus according to the present invention.
- FIG. 4 is a rear view of the water jet propulsion apparatus according to the present invention.
- FIG. 5 a is a side view of a cap according to the present invention.
- FIG. 5 b is a right side view, when viewed from the rear of the watercraft body, of a cap according to the present invention.
- FIG. 5 c a sectional view of a cap taken along line c-c of FIG. 5 b.
- FIG. 5 d is a cross section of a cap taken along line d-d of FIG. 5 b.
- a small planing watercraft 10 is a saddle-type small boat or watercraft.
- One of skill in the art will appreciate that the present invention is applicable to various types of watercraft, including, but not limited to, the type shown in FIGS. 1 and 2.
- An occupant sits on a seat 12 of a vessel body 11 , and can drive the small planing craft 11 by gripping a steering handle 13 with a throttle lever.
- the vessel body 11 has a floating body structure obtained by bonding a hull 14 and a deck 15 and forming a space 16 on the inside therebetween.
- An engine 20 is mounted in the space 16 and on the hull 14 , and a water jet propulsion apparatus or jet pump 30 as a propulsion device is driven by the engine 20 provided in the rear part of the hull 14 .
- the jet pump 30 has a duct 31 forming a channel 18 in communication with an intake 17 provided on the bottom of the vessel body 11 .
- An impeller 32 is disposed in the duct 31 , a bearing 33 of the impeller is provided in the duct 31 , and a cap 34 for sealing the rear end of the bearing 33 is also provided in the jet pump assembly 30 .
- a supporting shaft 35 supporting the rear part 32 b of the boss 32 a of the impeller 32 is rotatably supported by the bearing 33 via a ball bearing 33 a.
- a male screw 35 a is formed at the tip of the supporting shaft 35 and is screwed in a female screw portion formed in the rear part 32 b of the boss 32 a of the impeller 32 , thereby coupling the impeller 32 and the supporting shaft 35 . Therefore, the front part of the boss 32 a of the impeller 32 is coupled to the drive shaft 22 , the rear part 32 b of the boss is coupled to the supporting shaft 35 , and the impeller 32 rotates with the drive shaft 22 and the supporting shaft 35 .
- FIGS. 5 a, 5 b, 5 c, and 5 d are a side view, a right side view (seen from the rear of the vessel body), a cross section taken along line c-c of FIG. 5 b, and a cross section taken along line d-d of FIG. 5 b, respectively, of the cap 34 .
- a plurality of (twelve shown in FIG. 5) of stream straightening grooves 34 a are formed in the external face of the cap 34 .
- a cylindrical insertion portion 34 b inserted to the rear part of the bearing 33 is formed in the front part of the cap 34 , and three insertion holes 34 c for screws 36 (refer to FIG. 3) are formed between the stream straightening grooves 34 a.
- An attachment groove 34 b 1 for an O-ring (not shown) is formed in the cylindrical insertion part 34 b.
- An O-ring is attached to the cylindrical insertion part 34 b and the insertion part 34 b is inserted (force-fit) into the rear part of the bearing 33 as shown in FIG. 3, thereby attaching the cap 34 to the rear part of the bearing 33 by the screws 36 .
- a stationary blade 31 c 1 is formed facing toward the cap 34 .
- a bilge pipe 37 is inserted on the bottom of the watercraft for draining bilge water.
- a deflector 38 is rotatably attached to the rear part of the nozzle part 31 c.
- the impeller 32 is rotated by the rotation of the engine 20 via the drive shaft 22 , and water drawn in from the intake 17 is jetted from a jet port 31 c 2 of the nozzle part 31 c to the outside via the deflector 38 .
- the flow stream is straightened by the stationary vanes 31 b 1 and 31 c 1 and the stream straightening grooves 34 a of the cap 34 while the water stream passes through the duct 31 .
- the water stream leaving the deflector 38 thereby propels the vessel body 11 .
- the number of revolutions of the engine 20 e.g., the propulsion generated by the jet pump 30 is controlled by an operation of turning a throttle lever 13 a (refer to FIG. 2) of the steering handle 13 .
- An arm 38 a (refer to FIG. 4) of the deflector 38 is linked with the steering handle 13 via a control wire (not-shown) and is turned by the operation of the handle 13 , thereby enabling changes in course of the watercraft 10 .
- the water jet propulsion apparatus 30 as described above has the duct 31 forming the channel, the impeller 32 disposed in the duct 31 , the bearing 33 of the impeller 32 provided in the duct 31 , the cap 34 closing the rear end of the bearing 33 , and the stream straightening grooves 34 a formed in the external face of the cap 34 , the rotational component of the water stream close to the external face of the cap 34 can be reduced by the stream straightening grooves 34 a.
- the stream straightening grooves 34 a instead of a stream straightening plate, e.g., a stationary vane, in the external face of the cap 34 , a number of relatively smaller stream straightening grooves 34 a can be formed in the cap 34 .
- the grooves 34 a may be cut into the limited outer circumferential length of the cap 34 whose diameter is relatively small.
- the rotational component of the water stream close to the external face of the cap 34 can be sufficiently reduced with the present invention.
- the size of the cap 34 can be advantageously reduced with the present invention.
- stream straightening grooves 34 a are formed in the external face of the cap 34 , it is unnecessary to position the cap 34 with the other stationary vanes 31 b 1 and 31 c 1 . Therefore, the formation of stream straightening grooves 34 a in the external face of the cap 34 is particularly effective in the case where the stationary vane 31 c 1 is formed facing toward the cap 34 in the internal face of the duct 31 . Since the stream straightening grooves 34 a are formed instead of a larger stationary vane or straightening plate (see FIG. 6), interference between the cap 34 and the bilge pipe 37 is also avoided with the present invention.
Abstract
A water jet propulsion apparatus having a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing. In addition, at least one stream-straightening groove is formed in an external face of the cap. In the internal face of the duct, a stationary vane is formed in a portion facing toward the cap. Accordingly, a rotational component of a water stream close to the external face of a cap the bearing is substantially reduced, the size of the cap may be reduced, and cap position is not controlled by the position of the stationary vane.
Description
- This nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2001-270154 filed in Japan on Sep. 6, 2001, the entirety of which is herein incorporated by reference.
- 1. Field of the Invention
- The present invention relates to a water jet propulsion apparatus, and more particularly to a water jet propulsion apparatus for use in a watercraft.
- 2. Description of the Background Art
- A water jet propulsion apparatus of the background art, e.g., corresponding to Japanese Patent Laid-open No. Hei-5-105189, the entirety of which is hereby incorporated by reference, is shown in FIG. 6. The water jet propulsion apparatus has a
duct 2 forming a channel in communication with anintake 1 a provided on the bottom of ahull 1, animpeller 3 disposed in theduct 2, a bearing 4 of the impeller provided in theduct 2, and acap 5 closing the rear end of the bearing 4. Theduct 2 includes animpeller duct 2 a, astationary vane duct 2 b, and anozzle 2 c. The bearing 4 is formed integrally with thestationary vane duct 2 b via astationary vane 2b 1. - The
impeller 3 is fixed to adrive shaft 6. The front end of thedrive shaft 6 is coupled to the output shaft of an engine (not-shown) mounted on thehull 1, and therear end 6 a is rotatably supported by the bearing 4. Astationary vane 5 a is formed on the external face of thecap 5, and astationary vane 2c 1 is integrally formed on the internal face of thenozzle 2 c. Adeflector 7 is rotatably attached to the rear part of thenozzle 2 c. - In such a water jet propulsion apparatus, when the
impeller 3 is rotated by the rotation of the engine via thedrive shaft 6, water drawn in from theintake 1 a is passed through theimpeller duct 2 a and injected from ajet port 2c 2 of thenozzle 2 c to the outside via thedeflector 7 to propel thehull 1. The water flow is straightened by thestationary vanes 2b c 1 in a process of passing the flow through thestationary duct 2 b andnozzle 2 c. - In the above-described conventional water jet propulsion apparatus, since the
stationary vane 5 a is formed on thecap 5, the rotational component of a water stream near the center of thenozzle 2 c, e.g., around thecap 5 the rotational component of the water stream can be reduced and the water stream can be straightened to a certain degree. However, it is difficult to form a number ofstationary vanes 5 a within the limited length of the outer circumference of thecap 5 whose diameter is relatively small. - Therefore, the present inventors have determined that the rotational component of a water stream very close to the external face of the
cap 5 cannot be sufficiently reduced with the systems of the background art. Since thestationary vane 5 a is formed on the external face of thecap 5, thecap 5, including thestationary vane 5 a, is relatively large. In addition, thestationary vane 5 a formed on the external face of thecap 5 and thestationary vane 2c 1 formed on the internal face of thenozzle 2 c have to be repositioned. - The present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art.
- An object of the invention is to provide a water jet propulsion apparatus that can solve the above identified problems and/or sufficiently reduce the rotational component of the water stream close to the external face of the cap.
- An additional object of the present invention is to reduce the size of the cap while achieving the aforementioned objects.
- An additional object of the present invention is to provide a cap that does not require positioning between the cap and other stationary vanes.
- One or more of these and other objects are accomplished by a water jet propulsion apparatus comprising a duct forming a channel; an impeller being disposed within the duct; a bearing of the impeller provided in the duct, the bearing having a rear end and a front end; a cap closing the rear end of the bearing, the cap having an external face and a front portion; and at least one stream straightening groove being formed in the external face of the cap.
- One or more of these and other objects are further accomplished by a method of reducing a rotational component of a flow stream exiting a water jet propulsion apparatus for a watercraft, the method comprising installing a cap closing a rear end of a bearing for an impeller within a duct, the cap having an external face and a front portion; and forming at least one flow stream straightening groove within the external face of the cap for reducing the rotational component of the flow stream.
- The water jet propulsion apparatus including a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, a cap closing the rear end of the bearing, and stream straightening grooves formed in the external face of the cap provides a rotational component of a water stream close to the external face of the cap that is significantly reduced by the stream straightening grooves.
- Moreover, since it is sufficient to form the stream straightening grooves, e.g., not a stream straightening plate (stationary vane) in the external face of the cap, a number of stream straightening grooves can be formed in the limited outer circumference length of the cap whose diameter is typically relatively small. Accordingly, the rotational component of the water stream close to the external face of the cap can be sufficiently reduced with the present invention. In addition, the size of the cap can be reduced. Since stream straightening grooves are formed in the external face of the cap it becomes unnecessary to position the cap with the other stationary vanes. Therefore, formation of the stream straightening grooves in the external face of the cap is particularly effective in the case where a stationary vane is formed facing toward the portion facing the cap, e.g., in the internal face of the duct.
- Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
- The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
- FIG. 1 is a partial, side view of a small, planing watercraft having a water jet propulsion apparatus according to an embodiment of the present invention;
- FIG. 2 is a plan view of the watercraft shown in FIG. 1;
- FIG. 3 is a sectional view showing a water jet propulsion apparatus according to the present invention;
- FIG. 4 is a rear view of the water jet propulsion apparatus according to the present invention;
- FIG. 5a is a side view of a cap according to the present invention;
- FIG. 5b is a right side view, when viewed from the rear of the watercraft body, of a cap according to the present invention;
- FIG. 5c a sectional view of a cap taken along line c-c of FIG. 5b,
- FIG. 5d is a cross section of a cap taken along line d-d of FIG. 5b; and
- FIG. 6 is a sectional view of a propulsion apparatus of the background art.
- The present invention will hereinafter be described with reference to the accompanying drawings. FIG. 1 is a partial, side view of a small, planing watercraft having a water jet propulsion apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of the watercraft shown in FIG. 1. FIG. 3 is a sectional view showing a water jet propulsion apparatus according to the present invention. FIG. 4 is a rear view of the water jet propulsion apparatus according to the present invention. FIG. 5a is a side view of a cap according to the present invention. FIG. 5b is a right side view, when viewed from the rear of the watercraft body, of a cap according to the present invention. FIG. 5c a sectional view of a cap taken along line c-c of FIG. 5b. FIG. 5d is a cross section of a cap taken along line d-d of FIG. 5b.
- As shown in FIGS. 1 and 2, a
small planing watercraft 10 is a saddle-type small boat or watercraft. One of skill in the art will appreciate that the present invention is applicable to various types of watercraft, including, but not limited to, the type shown in FIGS. 1 and 2. An occupant sits on aseat 12 of avessel body 11, and can drive thesmall planing craft 11 by gripping asteering handle 13 with a throttle lever. Thevessel body 11 has a floating body structure obtained by bonding ahull 14 and adeck 15 and forming aspace 16 on the inside therebetween. Anengine 20 is mounted in thespace 16 and on thehull 14, and a water jet propulsion apparatus orjet pump 30 as a propulsion device is driven by theengine 20 provided in the rear part of thehull 14. - As also shown in FIG. 3, the
jet pump 30 has aduct 31 forming achannel 18 in communication with anintake 17 provided on the bottom of thevessel body 11. Animpeller 32 is disposed in theduct 31, a bearing 33 of the impeller is provided in theduct 31, and acap 34 for sealing the rear end of thebearing 33 is also provided in thejet pump assembly 30. - The
duct 31 has animpeller housing part 31 a, a bearinghousing part 31 b, and anozzle part 31 c. Theimpeller housing part 31 a is integrally formed with the bearinghousing part 31 b. Thebearing 33 is integrally formed in the bearinghousing part 31 b via astationary blade 31b 1. The front part of aboss 32 a of theimpeller 32 is engaged with aspline 22 b formed in the rear end of a drive shaft so that theimpeller 32 rotates with thedrive shaft 22. Thefront end 22 a of thedrive shaft 22 is coupled to an output shaft 21 (refer to FIG. 1) of theengine 20 mounted on thevessel body 11 via acoupler 23. - A supporting
shaft 35 supporting therear part 32 b of theboss 32 a of theimpeller 32 is rotatably supported by the bearing 33 via aball bearing 33 a. Amale screw 35 a is formed at the tip of the supportingshaft 35 and is screwed in a female screw portion formed in therear part 32 b of theboss 32 a of theimpeller 32, thereby coupling theimpeller 32 and the supportingshaft 35. Therefore, the front part of theboss 32 a of theimpeller 32 is coupled to thedrive shaft 22, therear part 32 b of the boss is coupled to the supportingshaft 35, and theimpeller 32 rotates with thedrive shaft 22 and the supportingshaft 35. - FIGS. 5a, 5 b, 5 c, and 5 d are a side view, a right side view (seen from the rear of the vessel body), a cross section taken along line c-c of FIG. 5b, and a cross section taken along line d-d of FIG. 5b, respectively, of the
cap 34. As seen in FIG. 5, a plurality of (twelve shown in FIG. 5) ofstream straightening grooves 34 a are formed in the external face of thecap 34. Acylindrical insertion portion 34 b inserted to the rear part of thebearing 33 is formed in the front part of thecap 34, and threeinsertion holes 34 c for screws 36 (refer to FIG. 3) are formed between thestream straightening grooves 34 a. Anattachment groove 34b 1 for an O-ring (not shown) is formed in thecylindrical insertion part 34 b. - An O-ring is attached to the
cylindrical insertion part 34 b and theinsertion part 34 b is inserted (force-fit) into the rear part of thebearing 33 as shown in FIG. 3, thereby attaching thecap 34 to the rear part of thebearing 33 by thescrews 36. In the part facing thecap 34 in the internal face of thenozzle 31 c, astationary blade 31c 1 is formed facing toward thecap 34. In thenozzle part 31 c, abilge pipe 37 is inserted on the bottom of the watercraft for draining bilge water. - A
deflector 38 is rotatably attached to the rear part of thenozzle part 31 c. In thejet pump 30 as described above, theimpeller 32 is rotated by the rotation of theengine 20 via thedrive shaft 22, and water drawn in from theintake 17 is jetted from ajet port 31c 2 of thenozzle part 31 c to the outside via thedeflector 38. The flow stream is straightened by thestationary vanes 31 b 1 and 31 c 1 and thestream straightening grooves 34 a of thecap 34 while the water stream passes through theduct 31. The water stream leaving thedeflector 38 thereby propels thevessel body 11. - The number of revolutions of the
engine 20, e.g., the propulsion generated by thejet pump 30 is controlled by an operation of turning athrottle lever 13 a (refer to FIG. 2) of thesteering handle 13. Anarm 38 a (refer to FIG. 4) of thedeflector 38 is linked with the steering handle 13 via a control wire (not-shown) and is turned by the operation of thehandle 13, thereby enabling changes in course of thewatercraft 10. - Since the water
jet propulsion apparatus 30 as described above has theduct 31 forming the channel, theimpeller 32 disposed in theduct 31, the bearing 33 of theimpeller 32 provided in theduct 31, thecap 34 closing the rear end of thebearing 33, and thestream straightening grooves 34 a formed in the external face of thecap 34, the rotational component of the water stream close to the external face of thecap 34 can be reduced by thestream straightening grooves 34 a. - Moreover, since it is sufficient to form the
stream straightening grooves 34 a, instead of a stream straightening plate, e.g., a stationary vane, in the external face of thecap 34, a number of relatively smallerstream straightening grooves 34 a can be formed in thecap 34. For example, thegrooves 34 a may be cut into the limited outer circumferential length of thecap 34 whose diameter is relatively small. Thus, the rotational component of the water stream close to the external face of thecap 34 can be sufficiently reduced with the present invention. - Further, the size of the
cap 34 can be advantageously reduced with the present invention. Further, sincestream straightening grooves 34 a are formed in the external face of thecap 34, it is unnecessary to position thecap 34 with the otherstationary vanes 31 b 1 and 31 c 1. Therefore, the formation ofstream straightening grooves 34 a in the external face of thecap 34 is particularly effective in the case where thestationary vane 31c 1 is formed facing toward thecap 34 in the internal face of theduct 31. Since thestream straightening grooves 34 a are formed instead of a larger stationary vane or straightening plate (see FIG. 6), interference between thecap 34 and thebilge pipe 37 is also avoided with the present invention. - The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims (19)
1. A water jet propulsion apparatus comprising:
a duct forming a channel;
an impeller being disposed within the duct;
a bearing of the impeller provided in said duct, said bearing having a rear end and a front end;
a cap closing the rear end of the bearing, said cap having an external face and a front portion; and
at least one stream straightening groove being formed in the external face of the cap.
2. The water jet propulsion apparatus according to claim 1 , further comprising a stationary vane being formed with an internal face of the duct and in a position facing toward said cap.
3. The water jet propulsion apparatus according to claim 1 , wherein the duct includes an impeller housing portion, a bearing housing portion, and a nozzle portion, wherein the impeller housing portion is integrally formed with the bearing housing portion.
4. The water jet propulsion apparatus according to claim 2 , wherein the duct includes an impeller housing portion, a bearing housing portion, and a nozzle portion, wherein the impeller housing portion is integrally formed with the bearing housing portion.
5. The water jet propulsion apparatus according to claim 3 , wherein the bearing is integrally formed in the bearing housing part with a stationary blade.
6. The water jet propulsion apparatus according to claim 4 , wherein the bearing is integrally formed in the bearing housing part with a stationary blade.
7. The water jet propulsion apparatus according to claim 1 , further comprising:
a drive shaft;
a spline formed in a rear end of the drive shaft; and
a boss for the impeller, said boss having a portion engaged with the spline formed in the rear end of the drive shaft.
8. The water jet propulsion apparatus according to claim 6 , further comprising:
a drive shaft;
a spline formed in a rear end of the drive shaft; and
a boss for the impeller, said boss having a portion engaged with the spline formed in the rear end of the drive shaft.
9. The water jet propulsion apparatus according to claim 1 , further comprising a cylindrical insertion portion being formed in the front portion of the cap, said cylindrical insertion portion operatively engaging the rear end of the bearing.
10. The water jet propulsion apparatus according to claim 8 , further comprising a cylindrical insertion portion being formed in the front portion of the cap, said cylindrical insertion portion operatively engaging the rear end of the bearing.
11. The water jet propulsion apparatus according to claim 1 , further comprising:
a plurality of said stream straightening grooves;
a plurality of fasteners; and
a plurality of insertion holes for said fasteners being formed between respective stream straightening grooves.
12. The water jet propulsion apparatus according to claim 10 , further comprising:
a plurality of said stream straightening grooves;
a plurality of fasteners; and
a plurality of insertion holes for said fasteners being formed between respective stream straightening grooves.
13. The water jet propulsion apparatus according to claim 9 , further comprising an attachment groove for an O-ring formed within the cylindrical insertion part.
14. The water jet propulsion apparatus according to claim 1 , further comprising a bilge pipe being inserted within the nozzle portion of the duct.
15. The water jet propulsion apparatus according to claim 3 , further comprising a deflector rotatably engaged with the nozzle portion.
16. The water jet propulsion apparatus according to claim 12 , further comprising a deflector rotatably engaged with the nozzle portion.
17. A method of reducing a rotational component of a flow stream exiting a water jet propulsion apparatus for a watercraft, said method comprising:
installing a cap closing a rear end of a bearing for an impeller within a duct, said cap having an external face and a front portion; and
forming at least one flow stream straightening groove within the external face of the cap for reducing the rotational component of the flow stream.
18. The method according to claim 17 , further comprising installing a plurality of the flow stream straightening grooves within the external face of the cap.
19. The method according to claim 18 , wherein the watercraft is a personal, saddle-driven watercraft.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001-270154 | 2001-09-06 | ||
JP2001270154A JP3963680B2 (en) | 2001-09-06 | 2001-09-06 | Water jet propulsion machine |
Publications (2)
Publication Number | Publication Date |
---|---|
US20030045183A1 true US20030045183A1 (en) | 2003-03-06 |
US6840826B2 US6840826B2 (en) | 2005-01-11 |
Family
ID=19095849
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/231,315 Expired - Fee Related US6840826B2 (en) | 2001-09-06 | 2002-08-30 | Water jet propulsion apparatus |
Country Status (3)
Country | Link |
---|---|
US (1) | US6840826B2 (en) |
JP (1) | JP3963680B2 (en) |
CA (1) | CA2395728C (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105339259A (en) * | 2013-03-15 | 2016-02-17 | S·布洛诺斯基 | Marine ducted propeller jet propulsion system |
CN106741784A (en) * | 2017-01-19 | 2017-05-31 | 罗朝霞 | Electric environment protecting hydrojet propelled ship |
US10597129B1 (en) | 2013-03-15 | 2020-03-24 | Stefan Broinowski | Marine ducted propeller mass flux propulsion system |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1824667A (en) * | 1926-07-20 | 1931-09-22 | Syndicat Vaproc | Rotary propeller |
US3083529A (en) * | 1959-03-24 | 1963-04-02 | Charles W F Hemilton | Hydraulic jet propulsion apparatus for water-borne craft |
GB1363637A (en) * | 1970-11-13 | 1974-08-14 | Ua Eng Ltd | Hydraulic jet propulsion means |
JPS6030599B2 (en) * | 1980-12-18 | 1985-07-17 | 川崎重工業株式会社 | Mixed flow water injection propulsion device |
US5123867A (en) * | 1990-05-10 | 1992-06-23 | Stefan Broinowski | Marine jet propulsion unit |
JPH05105189A (en) | 1991-10-14 | 1993-04-27 | Sanshin Ind Co Ltd | Water jet propulsion machine |
US5759074A (en) * | 1996-09-25 | 1998-06-02 | Brunswick Corporation | Impeller mounting system for a personal watercraft |
JP2000161126A (en) * | 1998-11-30 | 2000-06-13 | Yamaha Motor Co Ltd | Engine structure for small-sized vessel |
US6273768B1 (en) * | 2000-04-07 | 2001-08-14 | Bombardier Motor Corporation Of America | Water jet propulsion unit with counter-rotating impellers |
US6273769B1 (en) * | 2000-05-02 | 2001-08-14 | Chris W. Bell | Transparent thrust cone for monitoring oil level and condition in watercraft jet propulsion system |
-
2001
- 2001-09-06 JP JP2001270154A patent/JP3963680B2/en not_active Expired - Fee Related
-
2002
- 2002-07-26 CA CA002395728A patent/CA2395728C/en not_active Expired - Fee Related
- 2002-08-30 US US10/231,315 patent/US6840826B2/en not_active Expired - Fee Related
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105339259A (en) * | 2013-03-15 | 2016-02-17 | S·布洛诺斯基 | Marine ducted propeller jet propulsion system |
RU2666983C2 (en) * | 2013-03-15 | 2018-09-13 | Стефан БРОЙНОВСКИ | Marine ducted propeller jet propulsion system |
US10597129B1 (en) | 2013-03-15 | 2020-03-24 | Stefan Broinowski | Marine ducted propeller mass flux propulsion system |
CN111776184A (en) * | 2013-03-15 | 2020-10-16 | S·布洛诺斯基 | Marine duct propeller jet propulsion system |
CN106741784A (en) * | 2017-01-19 | 2017-05-31 | 罗朝霞 | Electric environment protecting hydrojet propelled ship |
Also Published As
Publication number | Publication date |
---|---|
US6840826B2 (en) | 2005-01-11 |
CA2395728C (en) | 2005-02-15 |
CA2395728A1 (en) | 2003-03-06 |
JP2003072686A (en) | 2003-03-12 |
JP3963680B2 (en) | 2007-08-22 |
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